What is the sumo term for a wrestler winning a tournament with no losses?

Zenshō-yūshō is the sumo term for winning a tournament with no losses.

The Japanese expression combines zenshō, meaning all wins, with yūshō, meaning championship. In a standard 15-day top-division tournament, a wrestler who wins every scheduled bout finishes 15–0 and earns a zenshō-yūshō. The achievement is one of the clearest measures of dominance in professional sumo.

A perfect championship is different from simply winning the tournament. A wrestler can take the title with one or more losses if every rival has a worse record. The term also differs from kachi-koshi, which means a winning record, and make-koshi, which means a losing record.

Zenshō-yūshō records are tracked across a wrestler’s career and can strengthen a case for promotion, especially at the highest ranks. However, promotion decisions also consider rank, consistency, quality of victories and the standards applied by the Japan Sumo Association.